/*
 * jpegtran.c
 *
 * Copyright (C) 1995, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains a command-line user interface for JPEG transcoding.
 * It is very similar to cjpeg.c, but provides lossless transcoding between
 * different JPEG file formats.
 */

#include "cdjpeg.h"				/* Common decls for cjpeg/djpeg applications */
#include "jversion.h"			/* for version message */

#ifdef USE_CCOMMAND				/* command-line reader for Macintosh */
#ifdef __MWERKS__
#include <SIOUX.h>				/* Metrowerks declares it here */
#endif
#ifdef THINK_C
#include <console.h>			/* Think declares it here */
#endif
#endif


/*
 * Argument-parsing code.
 * The switch parser is designed to be useful with DOS-style command line
 * syntax, ie, intermixed switches and file names, where only the switches
 * to the left of a given file name affect processing of that file.
 * The main program in this file doesn't actually use this capability...
 */


static const char *progname;	/* program name for error messages */
static char    *outfilename;	/* for -outfile switch */


LOCAL void usage(void)
/* complain about bad command line */
{
	fprintf(stderr, "usage: %s [switches] ", progname);
#ifdef TWO_FILE_COMMANDLINE
	fprintf(stderr, "inputfile outputfile\n");
#else
	fprintf(stderr, "[inputfile]\n");
#endif

	fprintf(stderr, "Switches (names may be abbreviated):\n");
#ifdef ENTROPY_OPT_SUPPORTED
	fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
#endif
#ifdef C_PROGRESSIVE_SUPPORTED
	fprintf(stderr, "  -progressive   Create progressive JPEG file\n");
#endif
	fprintf(stderr, "Switches for advanced users:\n");
	fprintf(stderr, "  -restart N     Set restart interval in rows, or in blocks with B\n");
	fprintf(stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n");
	fprintf(stderr, "  -outfile name  Specify name for output file\n");
	fprintf(stderr, "  -verbose  or  -debug   Emit debug output\n");
	fprintf(stderr, "Switches for wizards:\n");
#ifdef C_ARITH_CODING_SUPPORTED
	fprintf(stderr, "  -arithmetic    Use arithmetic coding\n");
#endif
#ifdef C_MULTISCAN_FILES_SUPPORTED
	fprintf(stderr, "  -scans file    Create multi-scan JPEG per script file\n");
#endif
	exit(EXIT_FAILURE);
}


LOCAL int parse_switches(j_compress_ptr cinfo, int argc, char **argv, int last_file_arg_seen, boolean for_real)
/* Parse optional switches.
 * Returns argv[] index of first file-name argument (== argc if none).
 * Any file names with indexes <= last_file_arg_seen are ignored;
 * they have presumably been processed in a previous iteration.
 * (Pass 0 for last_file_arg_seen on the first or only iteration.)
 * for_real is FALSE on the first (dummy) pass; we may skip any expensive
 * processing.
 */
{
	int             argn;
	char           *arg;
	boolean         simple_progressive;
	char           *scansarg = NULL;	/* saves -scans parm if any */

	/* Set up default JPEG parameters. */
	simple_progressive = FALSE;
	outfilename = NULL;
	cinfo->err->trace_level = 0;

	/* Scan command line options, adjust parameters */

	for(argn = 1; argn < argc; argn++)
	{
		arg = argv[argn];
		if(*arg != '-')
		{
			/* Not a switch, must be a file name argument */
			if(argn <= last_file_arg_seen)
			{
				outfilename = NULL;	/* -outfile applies to just one input file */
				continue;		/* ignore this name if previously processed */
			}
			break;				/* else done parsing switches */
		}
		arg++;					/* advance past switch marker character */

		if(keymatch(arg, "arithmetic", 1))
		{
			/* Use arithmetic coding. */
#ifdef C_ARITH_CODING_SUPPORTED
			cinfo->arith_code = TRUE;
#else
			fprintf(stderr, "%s: sorry, arithmetic coding not supported\n", progname);
			exit(EXIT_FAILURE);
#endif

		}
		else if(keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1))
		{
			/* Enable debug printouts. */
			/* On first -d, print version identification */
			static boolean  printed_version = FALSE;

			if(!printed_version)
			{
				fprintf(stderr, "Independent JPEG Group's JPEGTRAN, version %s\n%s\n", JVERSION, JCOPYRIGHT);
				printed_version = TRUE;
			}
			cinfo->err->trace_level++;

		}
		else if(keymatch(arg, "maxmemory", 3))
		{
			/* Maximum memory in Kb (or Mb with 'm'). */
			long            lval;
			char            ch = 'x';

			if(++argn >= argc)	/* advance to next argument */
				usage();
			if(sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
				usage();
			if(ch == 'm' || ch == 'M')
				lval *= 1000L;
			cinfo->mem->max_memory_to_use = lval * 1000L;

		}
		else if(keymatch(arg, "optimize", 1) || keymatch(arg, "optimise", 1))
		{
			/* Enable entropy parm optimization. */
#ifdef ENTROPY_OPT_SUPPORTED
			cinfo->optimize_coding = TRUE;
#else
			fprintf(stderr, "%s: sorry, entropy optimization was not compiled\n", progname);
			exit(EXIT_FAILURE);
#endif

		}
		else if(keymatch(arg, "outfile", 4))
		{
			/* Set output file name. */
			if(++argn >= argc)	/* advance to next argument */
				usage();
			outfilename = argv[argn];	/* save it away for later use */

		}
		else if(keymatch(arg, "progressive", 1))
		{
			/* Select simple progressive mode. */
#ifdef C_PROGRESSIVE_SUPPORTED
			simple_progressive = TRUE;
			/* We must postpone execution until num_components is known. */
#else
			fprintf(stderr, "%s: sorry, progressive output was not compiled\n", progname);
			exit(EXIT_FAILURE);
#endif

		}
		else if(keymatch(arg, "restart", 1))
		{
			/* Restart interval in MCU rows (or in MCUs with 'b'). */
			long            lval;
			char            ch = 'x';

			if(++argn >= argc)	/* advance to next argument */
				usage();
			if(sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
				usage();
			if(lval < 0 || lval > 65535L)
				usage();
			if(ch == 'b' || ch == 'B')
			{
				cinfo->restart_interval = (unsigned int)lval;
				cinfo->restart_in_rows = 0;	/* else prior '-restart n' overrides me */
			}
			else
			{
				cinfo->restart_in_rows = (int)lval;
				/* restart_interval will be computed during startup */
			}

		}
		else if(keymatch(arg, "scans", 2))
		{
			/* Set scan script. */
#ifdef C_MULTISCAN_FILES_SUPPORTED
			if(++argn >= argc)	/* advance to next argument */
				usage();
			scansarg = argv[argn];
			/* We must postpone reading the file in case -progressive appears. */
#else
			fprintf(stderr, "%s: sorry, multi-scan output was not compiled\n", progname);
			exit(EXIT_FAILURE);
#endif

		}
		else
		{
			usage();			/* bogus switch */
		}
	}

	/* Post-switch-scanning cleanup */

	if(for_real)
	{

#ifdef C_PROGRESSIVE_SUPPORTED
		if(simple_progressive)	/* process -progressive; -scans can override */
			jpeg_simple_progression(cinfo);
#endif

#ifdef C_MULTISCAN_FILES_SUPPORTED
		if(scansarg != NULL)	/* process -scans if it was present */
			if(!read_scan_script(cinfo, scansarg))
				usage();
#endif
	}

	return argn;				/* return index of next arg (file name) */
}


/*
 * The main program.
 */

GLOBAL int main(int argc, char **argv)
{
	struct jpeg_decompress_struct srcinfo;
	struct jpeg_compress_struct dstinfo;
	struct jpeg_error_mgr jsrcerr, jdsterr;

#ifdef PROGRESS_REPORT
	struct cdjpeg_progress_mgr progress;
#endif
	jvirt_barray_ptr *coef_arrays;
	int             file_index;
	FILE           *input_file;
	FILE           *output_file;

	/* On Mac, fetch a command line. */
#ifdef USE_CCOMMAND
	argc = ccommand(&argv);
#endif

	progname = argv[0];
	if(progname == NULL || progname[0] == 0)
		progname = "jpegtran";	/* in case C library doesn't provide it */

	/* Initialize the JPEG decompression object with default error handling. */
	srcinfo.err = jpeg_std_error(&jsrcerr);
	jpeg_create_decompress(&srcinfo);
	/* Initialize the JPEG compression object with default error handling. */
	dstinfo.err = jpeg_std_error(&jdsterr);
	jpeg_create_compress(&dstinfo);

	/* Now safe to enable signal catcher.
	 * Note: we assume only the decompression object will have virtual arrays.
	 */
#ifdef NEED_SIGNAL_CATCHER
	enable_signal_catcher((j_common_ptr) & srcinfo);
#endif

	/* Scan command line to find file names.
	 * It is convenient to use just one switch-parsing routine, but the switch
	 * values read here are ignored; we will rescan the switches after opening
	 * the input file.
	 */

	file_index = parse_switches(&dstinfo, argc, argv, 0, FALSE);
	jsrcerr.trace_level = jdsterr.trace_level;

#ifdef TWO_FILE_COMMANDLINE
	/* Must have either -outfile switch or explicit output file name */
	if(outfilename == NULL)
	{
		if(file_index != argc - 2)
		{
			fprintf(stderr, "%s: must name one input and one output file\n", progname);
			usage();
		}
		outfilename = argv[file_index + 1];
	}
	else
	{
		if(file_index != argc - 1)
		{
			fprintf(stderr, "%s: must name one input and one output file\n", progname);
			usage();
		}
	}
#else
	/* Unix style: expect zero or one file name */
	if(file_index < argc - 1)
	{
		fprintf(stderr, "%s: only one input file\n", progname);
		usage();
	}
#endif							/* TWO_FILE_COMMANDLINE */

	/* Open the input file. */
	if(file_index < argc)
	{
		if((input_file = fopen(argv[file_index], READ_BINARY)) == NULL)
		{
			fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]);
			exit(EXIT_FAILURE);
		}
	}
	else
	{
		/* default input file is stdin */
		input_file = read_stdin();
	}

	/* Open the output file. */
	if(outfilename != NULL)
	{
		if((output_file = fopen(outfilename, WRITE_BINARY)) == NULL)
		{
			fprintf(stderr, "%s: can't open %s\n", progname, outfilename);
			exit(EXIT_FAILURE);
		}
	}
	else
	{
		/* default output file is stdout */
		output_file = write_stdout();
	}

#ifdef PROGRESS_REPORT
	start_progress_monitor((j_common_ptr) & dstinfo, &progress);
#endif

	/* Specify data source for decompression */
	jpeg_stdio_src(&srcinfo, input_file);

	/* Read file header */
	(void)jpeg_read_header(&srcinfo, TRUE);

	/* Read source file as DCT coefficients */
	coef_arrays = jpeg_read_coefficients(&srcinfo);

	/* Initialize destination compression parameters from source values */
	jpeg_copy_critical_parameters(&srcinfo, &dstinfo);

	/* Adjust default compression parameters by re-parsing the options */
	file_index = parse_switches(&dstinfo, argc, argv, 0, TRUE);

	/* Specify data destination for compression */
	jpeg_stdio_dest(&dstinfo, output_file);

	/* Start compressor */
	jpeg_write_coefficients(&dstinfo, coef_arrays);

	/* ought to copy source comments here... */

	/* Finish compression and release memory */
	jpeg_finish_compress(&dstinfo);
	jpeg_destroy_compress(&dstinfo);
	(void)jpeg_finish_decompress(&srcinfo);
	jpeg_destroy_decompress(&srcinfo);

	/* Close files, if we opened them */
	if(input_file != stdin)
		fclose(input_file);
	if(output_file != stdout)
		fclose(output_file);

#ifdef PROGRESS_REPORT
	end_progress_monitor((j_common_ptr) & dstinfo);
#endif

	/* All done. */
	exit(jsrcerr.num_warnings + jdsterr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
	return 0;					/* suppress no-return-value warnings */
}
